Is that really an exploit? Seems like a stretch to call it that. Changing areas has the same effect as logging out. So if, instead of logging out, I stood in front of the elevator on fleet and clicked the button repeatedly, going from, say, the cartel bazaar to main level and back over and over - would that still be an exploit? Where do you draw the line between "exploit" and "working as intended"?
I'm not even sure I'd call it a loophole. It's just a different method of refreshing the mission list. If BW didn't want us refreshing the list, they wouldn't give us multiple options to do so, would they?
Yes, it's really an exploit (as is changing zones just to reset the list). If BW wanted people to always have access to all missions, that's what they would have coded. They wouldn't have bothered spending time using RNG to generate a subset of those missions if it was intended for you just to "manually" refresh the list when you didn't get what you wanted.
Also, if you read Khevar's post, he clearly identifies that [part of] his profits come from his spending extra time to log out and back in. Unless you think that the devs consider "repeatedly logging out and back in" as part of the intended crafting experience, you *know* it's an exploit.